1. “IMS in a Bottle”: Initial Experiences from an OpenSER-based Prototype Implementation of the 3GPP IP Multimedia Subsystem
Author:Joachim Fabini, Peter Reichl, Alexander Poropatich, Rainer Huber, Norbert Jordan
IEEE ICMB’06
Speaker：Lin, Wen-Jen
Advisor：Wu, Quincy

2. OutLine Introduction IMS CAMPARI Project Experiences and Challenges
IMS core components
IMS core network
CAMPARI Project
Experiences and Challenges
Charging
IPv4/v6 Interworking
Identity Management and USIM/ISIM Migration
Regulatory Aspects
Security and Authentication
2007/11/1

3. Introduction IMS(IP Multimedia Subsystem) by 3GPP CAMPARI project
End-to-end QoS
New IP-based services deployed fast
Flexible billing
CAMPARI project
Configuration, Architecture, Migration, Performance Analysis and Requirements of 3G IMS
“Minimal-optimal” IMS configuration with respect to architecture and QoS aspects.
2007/11/1

4. IMS High-Level requirements
Provide the middleware for rapid development of new services
Consolidate the infrastructure by deploying only one network
Voice is a part of the services
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5. IMS core components Reusing IETF protocols like SIP and Diameter.
Three main component classes:
CSCF (Call-Session Control Functions), are enhanced SIP proxies.
AS (Application Servers), are SIP-enabled
Database, like the Home subscriber Server (HSS)
Components for resource control
e.g. Media Resource Function Controller (MRFC)
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6. IMS core network
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7. CAMPARI Project
Goal of the CAMPARI is to experiment with a “minimal-optimal” IMS configuration.
IMS in a Bottle
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8. Experiences and Challenges
Charging
IPv4/v6 Interworking
Identity Management and USIM/ISIM Migration
Regulatory Aspects
Security and Authentication
2007/11/1

9. Charging Two fundamental charging approaches.
Offline charging (e.g. pay for bill)
Online charging (e.g. pre-pay credit)
Other charging mechanisms:
Session-based charging
Event-based charging
Flow-based charging
2007/11/1

10. IPv4/v6 Interworking Initially IMS based on using IPv6.
Can be solved by one of the following
Negotiate an agreement with his roaming partner in order to support IPv6.
Establish IPv6 tunnel bypass IPv4 GPRS nodes. (overhead)
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11. Identity Management and USIM/ISIM Migration
ISIM is an application residing on the Universal Integrated Circuit Card (UICC), similar to the SIM card.
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12. Regulatory Aspects
Emergency Services
Lawful Interception
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13. Security and Authentication
Security measures are not applicable.
Handsets do not support IPSec encryption.
High bandwidth links not widely available right now.
2007/11/1